GPT-5.3-Codex-Spark vs Nemotron 3 Ultra 500B

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

GPT-5.3-Codex-Spark is clearly ahead on the aggregate, 87 to 64. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3-Codex-Spark's sharpest advantage is in coding, where it averages 82.3 against 43.8. The single biggest benchmark swing on the page is LiveCodeBench, 80 to 41.

Nemotron 3 Ultra 500B gives you the larger context window at 10M, compared with 256K for GPT-5.3-Codex-Spark.

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. Nemotron 3 Ultra 500B only becomes the better choice if you need the larger 10M context window.

Agentic

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

85.6

Nemotron 3 Ultra 500B

62.8

90
Terminal-Bench 2.0
63
82
BrowseComp
69
83
OSWorld-Verified
58

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

Nemotron 3 Ultra 500B

43.8

91
HumanEval
66
80
SWE-bench Verified
42
80
LiveCodeBench
41
85
SWE-bench Pro
47

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

Nemotron 3 Ultra 500B

66.9

86
MMMU-Pro
61
91
OfficeQA Pro
74

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

Nemotron 3 Ultra 500B

77.2

94
SimpleQA
71
92
MuSR
69
97
BBH
85
91
LongBench v2
81
92
MRCRv2
85

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

Nemotron 3 Ultra 500B

57

97
MMLU
74
95
GPQA
73
93
SuperGPQA
71
91
OpenBookQA
69
88
MMLU-Pro
73
42
HLE
15
88
FrontierScience
67

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

Nemotron 3 Ultra 500B

84

92
IFEval
84

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

Nemotron 3 Ultra 500B

79.7

94
MGSM
81
89
MMLU-ProX
79

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

Nemotron 3 Ultra 500B

78

98
AIME 2023
74
98
AIME 2024
76
97
AIME 2025
75
94
HMMT Feb 2023
70
96
HMMT Feb 2024
72
95
HMMT Feb 2025
71
95
BRUMO 2025
73
98
MATH-500
84

Frequently Asked Questions

Which is better, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark is ahead overall, 87 to 64. The biggest single separator in this matchup is LiveCodeBench, where the scores are 80 and 41.

Which is better for knowledge tasks, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 57. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 43.8. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 78. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 77.2. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 62.8. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 66.9. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 84. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.3-Codex-Spark or Nemotron 3 Ultra 500B?

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 79.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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